This invention relates generally to the field of rotary dampers, and in particular, to rotary dampers for use in motor vehicle suspensions.
Rotary dampers, as used in vehicle suspensions, typically include a body with a means of fixed attachment and an axle or shaft that is used for rotary attachment. Bodies of vane type dampers have a chamber containing fluid and the axle is attached to a rotor with a vane or vanes closely fit into the fluid chambers. When torque is applied to the axle to cause rotation, the vanes apply pressure on the fluid to cause the fluid to flow through orifices or valves. The resistance of the fluid to flow through the orifices or valves causes the rotary damper to resist or damp the motion that is a result of the torque applied to the shaft. This type rotary damper generally includes some air space or a gas accumulator to allow for fluid thermal expansion and fill variation.
Currently, rotary dampers are manufactured with portions of the assembly, such as the valves, orifices, or accumulator, external to the rotor. This increases the complexity of manufacture and installation. Extra steps are required to install the rotary dampers in the motor vehicle. Parts are exposed, leaving them vulnerable to damage.
Rotary dampers typically provide the same damping regardless of the direction of axle rotation, limiting tuning options. The same torque is applied to the axle whether that is the proper amount of torque needed for that direction.
Accumulators located within the fluid chambers are exposed to external pressures as the vanes apply pressure to the fluid. This requires the accumulator walls be heavier and more rigid to withstand the external pressures.
Accordingly, it would be desirable to have a rotary damper that overcomes the disadvantages described.
One aspect of the invention provides all valves, orifices and an accumulator to be housed in the rotor, allowing easy assembly, a compact overall package, and a simple, rugged case.
Another aspect of the invention provides valves configured to provide independent control of damping for each direction of rotation.
Another aspect of the invention provides a connection to the accumulator that isolates the accumulator from pressures generated by damping pressures in the fluid chambers outside the rotor.
The invention provides the foregoing and other features, and the advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention and do not limit the scope of the invention, which is defined by the appended claims and equivalents thereof.